; load by default



(define (accumulate op init seq)
  (if (null? seq)
	  init
	  (op (car seq)
		  (accumulate op init (cdr seq)))))


(define (flatmap proc seq)
  (accumulate append [] (map proc seq)))


(define (remove item sequence)
  (filter (lambda (x) (not (= x item)))
		  sequence))


